Stuffing box or sealing means for compressors and the like



Dec. 18, 1928. 1,695,320 W. H. CARRIER STUFFING BOX 0R SEALING MEANS FORCOMPRESSORS Am) THE LIKE Original Filed April 5. 192-1 3 Sheets-Sheet 1Dec. 18,1928. R R 1,695,320

w. H. CARRIER sTuEEme ox 0E SEALING MEANS FOR COMPRE SSOR5 AND THE LIKE4 v Original Filed April 5- 921 3 Sheets-Sheet Patented Dec. 18, 1928.

-- UNITED STATES PATENT OFFICE.

WILLIS H. CARRIER, OF ESSEX FELLS, NEW JERSEY, ASSIGNOR TO CARRIERENG-I- NEERING CORPORATION, OF NEWARK, NEW JERSEY.

STUFFING BOX 0R SEALING MEANS FOR COMPRESSORS AND THE LIKE.

Original application filed April 5, 1 921,

which the compressor shaft passes out of the.

- compressor housing or casing. The invention CAD is particularlydesirable for use in connection with centrifugal compressors ofrefrigerating apparatus such as disclosed in my application Serial No.458,679 for United States Patent, No. 1,575,818. dated March 9,1926, ofwhich this application is a division. The invention, however,is notrestricted in its application to such use, but is applicable to elasticfluid compressors and the like for other purposes where it is importantto seal the shaft opening against the leakage of gas or airtherethrough, and to do this with the minimum friction.

The objects of my invention are to provide a stufiing box or sealingarrangement for compressors and the like that will be substantiallyfrictionless notwithstanding the high speed of the rotary compressor,will seal perfectly against any necessary vacuum or against any moderatepressure up to atmospheric pressure or more while the machine isrunning, and will also effectually prevent any escape of the refrigerantvapor and any ingress of air when the rotation of the compressor isstopped; also to provide a practical stufling box or sealing mechanismin which a liquid sealing medium effects a substantially frictionlessclosure when the compressor is running, and a valve or mechanical deviceforms the closure when the compressor is not running; also to preventthe sealing liquid of the stuffing box from leaking anywhere into thecompressor, so as to preclude the mechanical trouble and contaminationof the refrigerant which would otherwise result; and also to improvestufling boxes or sealing devices in the other respects hereinafterdescribed and set forth in the claims.

In the accompanying drawings Fig. 1 is a sectional elevation of astufiing box embodying my invention.

Figs. 2 and 3 are fragmentary sections thereof showing respectively theclosed and open positions of the stuffing box valve.

Fig. 4 is a transverse sectional elevation thereof on line 44, Fig. 1.

Serial No. 458,679. Divided and this application filed January 9, i1926. Serial No. 80,384.

Fig. 7 is a vertical section thereofon line 7-7, Fig. 1. Y

Fig 8 is a sectional elevation of the lower end of the'stuifing box aschanged for use on a vertical compressor.

The stufling box is preferably constructed as follows: The stuffing boxcasing which surrounds the compressor shaft 15 is preferably composed ofseparable halves or sections '70 and 71, each extending part way aroundthe shaft, and an outer end plate or head 72"having a central openingthrough which the shaft passes. These parts or sections of the casingare. bolted or otherwise tightly secured together and the casing isstationarily secured, as by bolts 74 to the pressure or discharge end74* of the casing of the compressor. Each of the joints between theparts of the stufling box and between the stufling box and the shell ofthe compressor is made gas tight, preferably by means of soft metalgaskets or acking strips 75 supplemented by a liqu1d seal. 76 representsa circular channel for the sealing liquid in the joint between thestuffing box and the compressor casing, and 76 represents a similarsealing channel in the joint between the head 72 and the two halfsections of the stufliug box. These channels are connected by sealingchannels 76', see Fig. 7, in the joints between the half sections 70 and71 of the box, and sealing liquid is supplied to the channels fromstorage chambers 77 and 7 7' in the stuffing box through suitableconnecting ducts 77" and 77 7 The stufiing box casing is provided with avacuum chamber 78 surrounding the compressor shaft adjacent to thecompressor casing, and this chamber is connected by a suitable pipe orconduit 7 8 with the suction end of the compressor or with one of theintermediate compressor stages-so that a vacuum is maintained in thechamber 78 for the purpose of preventing condensation of the refrigerantvapor 1n the stufling box between the compressor and the liquid seal,about to be described. j

' The stuffing box is provided with an annular sealing chamber 79surrounding the compressor shaft, and is also preferably provided onopposlte sides of this sealing chamber with auxiliary annular chambers80 and 81. Pressed on or otherwise fixed by a gas tight joint to thecompressor shaft, is an impeller sleeve 82 provided with annular flanges83 and 84 and impeller blades 83 and 84 which project respectively intoand are adapted to rotate in the chambers and 81, and between theseimpellers with an annular flange 85 which projects into the sealingchamber 79 and is provided on its opposite sides with impeller blades 86and 86 adapted to rotate in the sealing chamber. The impeller chamber 80is connected to the sealing chamber 79 by one or more ducts 87 whichextend inwardly from the outer portion of the chamber 80 and connectwith the sealing chamber 79 between its ends, and the inner portion ofthe sealing chamber 79, at the opposite side of the sealing flange, isconnected with the other impeller chamber 81 near its outer periphery byone or more ducts 81*. A duct'87 connects the inner impeller chamber 80with the vacuum chamber. Sealing liquid, which is supplied to the outerimpeller chamber 81, as explained later, is pumped by the centrifugalaction of the impellers in this chamber into the sealing chamer 79 andthe impellers in the chamber 80 act to create a pressure which preventsthe liquid from passing out of the sealing chamber into the chamber 80.A body of sealing liquid is thus held by centrifugal force in the outerperipheral portion of the sealing chamber 79, into which liquid projectsthe outer edge of the flange 85 in this chamber, thereby forming aliquid seal which prevents the passage of vapor or air through the shaftopening of the stuffing box either out of or into the compressor. Theimpellers in the chambers 80 and 81 at opposite sides of the sealingchamber supplement the impellers in the latter chamber in producing aneffective liquid seal.

88 represents a valve or sleeve which surrounds the compressor shaftoutwardly beyond the sleeve 82 and is adapted to slide lengthwise on theshaft into and out of contact with the end face of the sleeve 82. Theadjacent ends of the valve 88 and the sleeve 82 are preferably ofcomplementary frustoconical shape so as to form a tight joint when thevalve seats against the end of the sleeve. The end'of the sleeve 82 actsby centrifugal force to impel sealing liquid which is delivered to thespace between the valve and the sleeve 82, through a duct 89 into the.

outer impeller chamber 81. An annular groove 90 is formed between theadjacent.

ends of the valve 88 and sleeve 82, preferably in the inner end of thevalve, and sealing liquid is supplied from a suitable reservoir througha pipe 91 and duct 91 to this groove. The valve 88 is connected to theouter end of the stuffing box and held from turning, preferably by studsor bolts 92 which are screwed or otherwise suitably fixed to the head ofthe stuffing box and extend through perforated lugs on an outwardlyprojecting flange 93 on the valve. Springs 94 surrounding these bolts orstuds between the lugs and the end of the stuffing box tend to open thevalve or move it outwardly away from the end of the sleeve 82. 95indicates an annular metal bellows or extensible sleeve which surroundsthe adjacent ends of the sleeve 82, and the valve, and is tightlysecured at its opposite ends to the outer end of the stuffing box and tothe outwardly projecting flange 93 of the valve. This extensible sleeveforms a gas and liquid tight chamber around the adjacent ends of thevalve 88 and sleeve 82, whereby the sealing liquid is confined and theloss of vacuum or the entrance of air prevented while, nevertheless,permitting the opening and closing of the valve. Absorbent material orwicking 95' is preferably provided in the cavities of the expansiblesleeve 95 so that the sealing liquid will be absorbed by this materialand retained in the sleeve,

thus largely preventing the liquid from run-- ning out of the sleevewhen the compressor is stopped.

The valve is adapted to be moved outwardly or opened and retained openwhile the compressor is running, and closed when the rotation of thecompressor stops by an operating mechanism in the nature of acentrifugal governor. This device comprises a ring 96 which is fixed tothe compress'br shaft by screws 97 or other suitable fastenings, and amovable ring 98 which is adapted to slide endwise on the shaft and isprevented from turning thereon preferably by means of a key or feather99 working in a longitudinal groove 100 in the ring 98. The two rings 96Ill and 98 are connected by governor links 101 and 102 which are pivotedtogether at their adjacent ends. and at their outer ends are pivotedrespectively to the fixed and sliding rings 96 and 98. The sliding ring98 is provided with studs or fingers 103 which project into an annulargroove 10a in the outer end of the valve sleeve 88 so that the valve ismoved outwardly or inwardly by the corresponding movements of the ring98. 105 indicates a coil spring surrounding the fixed. and movable rings96 and 98 and acting against shoulders thereon to press the movable ring98 and the valve inwardly to close the valve. When the compressor isrunning, the centrifugal action of the governor links 101, 102 moves thering 98 and the connected valve outwardly against the action of theclosing spring 105. The small springs 94 surrounding the studs or bolts92 are lighter than the valve closing spring'105 and do not prevent thevalve from being closed by this spring when the compressor stops, butthe springs 94 assist in opening the valve when starting up thecompressor in case the valve sticks. The adjacent ends of the governorrings 96 and 98 are adapted to abut to limit the openipg movement of thering 98, and the opening movement of the valve 88 is limited by theengagement of its lugs with adjustable nuts or stops 106 on the studs92. When the ring 98 and valve are thus arrested in their outer or openpositions, there will be a clearance between the valve opening fingers103 and the faces of the groove 104 into which they extend so that therewill be no friction between these parts when the valve is open and thecompressor is running.

107 represents the reservoir for supplying the sealing liquid to thestufling box. The reservoir can be of any suitable type, but it ispreferably supported on an upright tube 108 secured to the stuffing boxand connecting the reservoir with the storage chamber 77 in the stuflingbox so that the latter is filled through the reservoir and tube. Thereservoir is preferably provided with a gage glass 109 and with a sightfeedvalve 110 in the discharge pipe 91 which leads to the seat of thevalve 88, so that the feed of the sealing liquid can be observed andregulated as required. A separate discharge pipe 111 with a sight feedor regulating valve 112 delivers the sealing liquid to the bore of thevalve sleeve 88 to lubricate this valve. The feed pipes are preferablyflexible or constructed so as not to interfere with the movement of thevalve 88. 113 represents a liquid return duct leading from the firstimpeller chamber 81 and connecting wit-h a pipe 114, preferablyextending up through thesupporting tube 108 into the reservoir with itsupper end above the high level of the liquid in the reservoir. Anysurplus sealing liquid, above the quantity utilized in forming theliquid seal in the sealing chamber 79, is returned through the pipe 114to the reservoir by the impeller I or centrifugal pump in the firstimpellerchamber 81. In this way acontinuous sup ply of the sealingliquid, more than ample.

to make the seal, is continuously circulated through the extensibleliquid chamber surrounding the valve seat and the connectingimpellerchamber 81. Any suitable sealing liquid, such as glycerine, water or oilcan be used. \Vhen the compressor is stopped, the closing of the valve88 automatically stops the discharge of the sealing liquid and preventswaste thereof or its leakage into the compressor. the valve is fed withthe sealing liquid when the valve is closed and forms a liquid seal"supplementing the valve.

\Vhen the stuffing box .is placed vertically, an annular cup or chamber115, see Fig. 8, is used, which surrounds the lower end of the vimpellersleeve 82 and has an inner tubular wall 116 which extends upwardlyaround the The groove 90in the end of compressor shaft in an annularrecess 117 in the impeller sleeve. When the compressor is' stopped, thesealing liquid is adapted to run out'of the impeller chambers 79, 80,and 81 and collect in this cup, which prevents the liquid from runninginto the compressor. This cup is connected by a pipe or passage 118 withthe suction end of one of the compressor stages, and forms a vacuumchamber serving the same function" as the vacuum ghamber in thehorizontally arranged stufiing ox.

The stufling box described provides a centrifugal liquid seal free fromsubstantial friction when the compressor is running, and a valve ormechanical closure when the rotation of the compressor stops, and alwaysinsures a gas tight closure of the opening for the compression shaft.This stufling box is applicable to high speed rotary compressors, vacuumpumps or other rotary machines where it is necessary to prevent allleakage,

either inwardly or outwardly around the maforms a li uid seal for saidshaft 0 enin when the compressor is running.

2. The combination wi 11 a fluid compressor having a rotary shaftextending through an opening in the compressor casing, of a valve andvalve seat which surround said shaft and cooperate when thevalveisseated to form a closure for said shaft opening, mechanism forholding said valve and valve seat out of contact when the compressor isrunning, a sealing chamber surrounding said shaft, an-impeller whichrotates with said shaft in said sealing chamber, and supply and returnconnections for'sealing liquid to and from said sealing chamber, wherebysaid impeller maintains a centrifugal liquid seal for said shaft openingwhen the compressor 3. The combination. with a fluid compressor having arotary shaft extendmg through is riinning.

an opening in the compressor casing, .of a

valve and valve seat which surround said shaft and cooperate when thevalve is seated to form a closure "for said shaft opening, mechanism forholding said valve and valve seat out of contact when the compressor isrunning, a reservoir for a sealin liquid, a sealing chamber surroundingsai shaft, an impeller which'rotates with said shaft in said sealingchamber, and supply and return connections between said reservoir andsealing chamber, whereby said impeller maintains a centrifugal liquidseal for said shaft opening when the compressor is runnin 4. Thecombination with a fluid compressor having a rotary shaft extendingthrough an opening in the compressor casing, of a valve and valve seatwhich surround said shaft and cooperate when the valve is seated to forma closure for said. shaft opening, mechanism for holding said valve andvalve seat out of contact when the compressor is running, a sealingchamber surrounding said shaft, an impeller which rotates with saidshaft in said sealing chamber, a connection for supplying sealing liquidto the space between the valve and valve seat, and a liquid returnconnection from said sealing chamber whereby the impeller maintains acirculation of sealing liquidbetween the valve and valve seat and formsa liquid seal for the shaft opening when the compressoris running.

5. The combination with a fluid compressor having a rotary shaftextending through an opening in the compressor casing, of a valve andvalve seat which surround said shaft and cooperate when the valve isseated to form a closure for said shaft opening, centrifugal mechanismfor holding said valve and valve seat out of contact when the comprcssoris running, and means which maintain a circulation of sealing liquidbetween said 'valve and valve seat and form a liquid seal for said shaftopening when the compressor is running.

6. The combination with a fluid compressorhaving a rotary shaftextending through @11 opening in the compressor casing, of a (tiltjshaft and cooperate when the valve is seated to form a closure for saidshaft opening,

valve and valve seat which surround said operating mechanism for holdingsaid valve out of contact with said valve seat when the compressor isrunning, said valve and operating mechanism being relatively movable, astop device for relieving friction between said operating mechanism andsaid valve when the valve is unseated, and means which maintain a-liquidseal for said shaft opening when the cinppressor is running.

7. Thefcom-zegnation with a gaseous fluid compressorimavmg a rotaryshaft extending through an opening in the compressor casing, of a valveand valve seat which cooperate when the valve is seated to form aclosure for said shaft opening, mechanism which operates to hold thevalve and valve seat out of contact when the compressor is running, asealing chamber surrounding said shaft, a source of supply for sealingliquid and supply and return connections between the same and saidsealing chamber, and means operating when the compressor is running tomaintain a liquid seal for said shaft opening in said sealing chamber.

8. The combination with a gaseous fluid compressor having a rotary shaftextending through an opening in the compressor casing, of a valve andvalve seat which cooperate when the valve is seated to form a closurefor said shaft opening, and means operating when the compressor isrunning to provide a liquid seal for. said shaft'opening, there being aspace surrounding said shaft between the compressor and said liquidseal, said space communicating with a low pressure part of thecompressor whereby a partial vacuum is maintained by said space toprevent condensation therein of the fluid being compressed.

9. The combination with a gaseous fluid compressor having a rotary shaftextending through an opening in the compressor casing, a sealing chambersurrounding said shaft, and means for circulating a sealing liquidthrough. and maintaining a liquid seal in said chamber, there being aspace surrounding said shaft between the compressor and said sealingchamber, said space communicating with said sealing chamber and rrunning, a sealing chamber surrounding said shaft, an impeller whichrot-ates with said shaft in said sealing chamber, impeller chambers atopposite sides of said sealing chamber and communicating therewith,impellers which rotate in said impeller chambers for moving sealingliquid from said impeller chambers to said sealing chamber, a sealingliquid supply communicating with one of said impeller chambers, and aliquid return connection communicating with sa1d sealing chamber. I

WILLIS H. CARRIER.

